Soko Kawashima1, Mitsumasa Kishimoto2, Yoshinori Komagata3 and Shinya kaname4, 1Kyorin University, Mitaka Tokyo, Japan, 2Kyorin University School of Medicine, Yokohama, Japan, 3Kyorin University School of Medicine, Tokyo, Japan, 4Kyorin University, Tokyo, Japan
Background/Purpose: Contrary to many Western countries, MPO-ANCA-associated vasculitis (MPO-AAV) is dominant in Japan. The therapeutic response to rituximab (RTX) may differ. Therefore, we conducted a retrospective analysis of the clinical database of the 66 AAV-patients in our hospital treated with RTX.
Methods: All patients met the CHCC classification criteria for MPA and GPA at disease onset. Sixty-six patients [41(64%) females)] followed for at least six months since 2013 (up to Oct 2021) were analysed for clinical course, including remission rates. Remission was defined as Birmingham Vasculitis Activity Score (BVAS) 0 at six months. Disease flare defined as increased disease activity required intensification of immunosuppressive therapy.
Results: Of the 66 patients (32 MPO-MPA, 17 MPO-GPA, and 17 PR3-GPA),62 patients [31 newly diagnosed(N-group) or 31 relapsing diseases (R-group)] received a remission induction with RTX and 4 patients received maintenance RTX therapy. The mean age at the initiation of RTX was 65.9±16.4 years, 28 patients (42%) over 75 years, mean BVAS was 10.6±7.5, 47% had renal involvement, and mean serum creatinine was 1.6±1.2 mg/dl. Overall, 82% (51/62 patients) achieved remission at six months. Eighty-four percent (26/31) in N-group and 39% (12/31) in R-group received glucocorticoid pulse therapy. Mean daily dose of PSL at RTX initiation/six months were 46.5±11.2 mg/10.1±0.2 mg and 26.8±16.2 mg/9.7±0.2mg in newly diagnosed and relapsing cases, respectively. There were three refractory cases who switched another induction therapy (1MPO-MPA, 1MPO-GPA, 1 PR3-GPA) within six months. After mean follow-up 2.6±2.2 years, 39/60 patients received maintenance RTX therapy (six patients lost to follow-up). Maintenance therapy was given more often based on changes in CD19+ counts and/or ANCA titer in 57% (22/39 cases) as compared to scheduled administration every 6 months. There were 9 relapses in 7 cases (mean 16.6 ± 9.2 months after the last RTX), with 67% (6/9) of relapse seen in GPA (3 in MPO-MPA, 1 in MPO-GPA, 5 in PR3-GPA). Retreatment with RTX successfully induced remission in all relapsed cases. Death occurred in 9 patients [5 infection, 2 cardiovascular disease, 1 malignancy (unrelated), 1 AAV], three of which were due to infection within 6 months.
Conclusion: These results showed that RTX is effective and has an acceptable safety profile in relatively elder AAV patients in daily practice.
